eigrpd/eigrp_siaquery.c

   1 /*
   2  * EIGRP Sending and Receiving EIGRP SIA-Query Packets.
   3  * Copyright (C) 2013-2014
   4  * Authors:
   5  *   Donnie Savage
   6  *   Jan Janovic
   7  *   Matej Perina
   8  *   Peter Orsag
   9  *   Peter Paluch
  10  *
  11  * This file is part of GNU Zebra.
  12  *
  13  * GNU Zebra is free software; you can redistribute it and/or modify it
  14  * under the terms of the GNU General Public License as published by the
  15  * Free Software Foundation; either version 2, or (at your option) any
  16  * later version.
  17  *
  18  * GNU Zebra is distributed in the hope that it will be useful, but
  19  * WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21  * General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License along
  24  * with this program; see the file COPYING; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  26  */
  27
  28 #include <zebra.h>
  29
  30 #include "thread.h"
  31 #include "memory.h"
  32 #include "linklist.h"
  33 #include "prefix.h"
  34 #include "if.h"
  35 #include "table.h"
  36 #include "sockunion.h"
  37 #include "stream.h"
  38 #include "log.h"
  39 #include "sockopt.h"
  40 #include "checksum.h"
  41 #include "md5.h"
  42 #include "vty.h"
  43
  44 #include "eigrpd/eigrp_structs.h"
  45 #include "eigrpd/eigrpd.h"
  46 #include "eigrpd/eigrp_interface.h"
  47 #include "eigrpd/eigrp_neighbor.h"
  48 #include "eigrpd/eigrp_packet.h"
  49 #include "eigrpd/eigrp_zebra.h"
  50 #include "eigrpd/eigrp_vty.h"
  51 #include "eigrpd/eigrp_dump.h"
  52 #include "eigrpd/eigrp_macros.h"
  53 #include "eigrpd/eigrp_topology.h"
  54 #include "eigrpd/eigrp_fsm.h"
  55 #include "eigrpd/eigrp_memory.h"
  56
  57 /*EIGRP SIA-QUERY read function*/
  58 void eigrp_siaquery_receive(struct eigrp *eigrp, struct ip *iph,
  59                             struct eigrp_header *eigrph, struct stream *s,
  60                             struct eigrp_interface *ei, int size)
  61 {
  62         struct eigrp_neighbor *nbr;
  63         struct TLV_IPv4_Internal_type *tlv;
  64
  65         uint16_t type;
  66
  67         /* increment statistics. */
  68         ei->siaQuery_in++;
  69
  70         /* get neighbor struct */
  71         nbr = eigrp_nbr_get(ei, eigrph, iph);
  72
  73         /* neighbor must be valid, eigrp_nbr_get creates if none existed */
  74         assert(nbr);
  75
  76         nbr->recv_sequence_number = ntohl(eigrph->sequence);
  77
  78         while (s->endp > s->getp) {
  79                 type = stream_getw(s);
  80                 if (type == EIGRP_TLV_IPv4_INT) {
  81                         struct prefix dest_addr;
  82
  83                         stream_set_getp(s, s->getp - sizeof(uint16_t));
  84
  85                         tlv = eigrp_read_ipv4_tlv(s);
  86
  87                         dest_addr.family = AFI_IP;
  88                         dest_addr.u.prefix4 = tlv->destination;
  89                         dest_addr.prefixlen = tlv->prefix_length;
  90                         struct eigrp_prefix_entry *dest =
  91                                 eigrp_topology_table_lookup_ipv4(
  92                                         eigrp->topology_table, &dest_addr);
  93
  94                         /* If the destination exists (it should, but one never
  95                          * know)*/
  96                         if (dest != NULL) {
  97                                 struct eigrp_fsm_action_message msg;
  98                                 struct eigrp_nexthop_entry *entry =
  99                                         eigrp_prefix_entry_lookup(dest->entries,
 100                                                                   nbr);
 101                                 msg.packet_type = EIGRP_OPC_SIAQUERY;
 102                                 msg.eigrp = eigrp;
 103                                 msg.data_type = EIGRP_INT;
 104                                 msg.adv_router = nbr;
 105                                 msg.metrics = tlv->metric;
 106                                 msg.entry = entry;
 107                                 msg.prefix = dest;
 108                                 eigrp_fsm_event(&msg);
 109                         }
 110                         eigrp_IPv4_InternalTLV_free(tlv);
 111                 }
 112         }
 113         eigrp_hello_send_ack(nbr);
 114 }
 115
 116 void eigrp_send_siaquery(struct eigrp_neighbor *nbr,
 117                          struct eigrp_prefix_entry *pe)
 118 {
 119         struct eigrp_packet *ep;
 120         uint16_t length = EIGRP_HEADER_LEN;
 121
 122         ep = eigrp_packet_new(EIGRP_PACKET_MTU(nbr->ei->ifp->mtu), nbr);
 123
 124         /* Prepare EIGRP INIT UPDATE header */
 125         eigrp_packet_header_init(EIGRP_OPC_SIAQUERY, nbr->ei->eigrp, ep->s, 0,
 126                                  nbr->ei->eigrp->sequence_number, 0);
 127
 128         // encode Authentication TLV, if needed
 129         if ((nbr->ei->params.auth_type == EIGRP_AUTH_TYPE_MD5)
 130             && (nbr->ei->params.auth_keychain != NULL)) {
 131                 length += eigrp_add_authTLV_MD5_to_stream(ep->s, nbr->ei);
 132         }
 133
 134         length += eigrp_add_internalTLV_to_stream(ep->s, pe);
 135
 136         if ((nbr->ei->params.auth_type == EIGRP_AUTH_TYPE_MD5)
 137             && (nbr->ei->params.auth_keychain != NULL)) {
 138                 eigrp_make_md5_digest(nbr->ei, ep->s, EIGRP_AUTH_UPDATE_FLAG);
 139         }
 140
 141         /* EIGRP Checksum */
 142         eigrp_packet_checksum(nbr->ei, ep->s, length);
 143
 144         ep->length = length;
 145         ep->dst.s_addr = nbr->src.s_addr;
 146
 147         /*This ack number we await from neighbor*/
 148         ep->sequence_number = nbr->ei->eigrp->sequence_number;
 149
 150         if (nbr->state == EIGRP_NEIGHBOR_UP) {
 151                 /*Put packet to retransmission queue*/
 152                 eigrp_fifo_push(nbr->retrans_queue, ep);
 153
 154                 if (nbr->retrans_queue->count == 1) {
 155                         eigrp_send_packet_reliably(nbr);
 156                 }
 157         } else
 158                 eigrp_packet_free(ep);
 159 }